Gastroenteritis attributable to viruses or bacteria is a condition that causes irritation and inflammation of the stomach and intestines (the gastrointestinal tract). Other causes include parasites, food allergens, drug reactions to antibiotics, and ingestion of toxic plants. Vomiting caused by acute gastroenteritis is very common in children and adolescents and is a very common reason for children and adolescents attending emergency departments. Intestinal irritation caused by gastroenteritis appears to be the main stimulus for vomiting. As the virus or bacteria invades the mucosal cells of the upper gastrointestinal tract, it disrupts the normal sodium and osmotic intracellular balance and as a result excessive intracellular fluids are lost producing cellular fluid depletion.
Acute gastritis is the irritation and inflammation of the stomach's mucous lining. Gastritis may be caused by a chemical, thermal, or bacterial insult. For example, drugs such as alcohol, aspirin, and chemotherapeutic agents may cause an attack of gastritis. Likewise, hot, spicy, rough, or contaminated foods may bring about an attack. People experiencing gastritis typically vomit.
Hyperemesis gravidarumn (“HG”) is a disorder in which extreme, persistent nausea and vomiting occur during pregnancy. A woman might have hyperemesis gravidarum if she is pregnant and she vomits more than three to four times per day; so much that she loses more than 10 pounds; so much that she feels dizzy and lightheaded; or so much that she is becoming dehydrated.
Vomiting, from whatever cause, occurs because of the stimulation of the two centers located in the brain, the chemoreceptor trigger zone and the vomiting center. If a person cannot drink fluids to replenish this loss, intravenous fluids may be required to put fluid back into your body (rehydration). Antiemetic medications are known to alleviate vomiting by inhibiting the body's chemoreceptor trigger zone (CTZ) or by a more direct action on the brain's vomiting center.
Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, meaning symptoms are caused by changes in how the GI tract works. IBS is a group of symptoms that occur together. The key symptom of IBS is abdominal pain and/or discomfort. The pain or discomfort is associated with a change in the frequency or consistency of stool. The altered bowel habit may be chronic or recurrent diarrhea, or constipation. Some people have both diarrhea and constipation, just at different times. Bloating or distention in the abdomen is also common. Diarrhea is one of the symptoms often associated with IBS. IBS with diarrhea is sometimes referred to as IBS-D.